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Was this an order by a Court? Or how do you mean change ownership?
Then yes it can be changed. What do want it changed from/to?
Please clarify what you are changing from - to. E.g. exisiting company name to a new company name? Your individual names to a company name?
If the sale was agreed by the Creditors and Court it is irrespective whether it was sold privately or by auction. The objection should have been put in place not with the Land Registry but with the receiver to object to the sale and the reasons for doing so. It sounds like it quite far progressed, despite there being a court order against the receiver. You can put in an application to the Land Registry but it is unlikely they will have power over this, you will need to instruct a solicitor and make a claim against why it was being sold without your consent in the first place. Hope his helps.
As mentioned, you can however I do not think it will be accepted. The Land Registry do not make "decisions", they simply carry out registration formalities from the instructions they receive. So if you put in an application it will probably be rejected, not because they have made a decision to reject it but because there is not enough evidence to undo the application already done.
That is probably because the application was already submitted. You can submit an emergency application as you say considering you only got the letter today, and see what they say.